It is known that acetylenic unsaturated compounds can be carbonylated in the presence of a hydroxyl-containing compound such as an alcohol, phenol water or a carboxylic acid to produce alpha,beta-olefinic unsaturated esters, acids or anhydrides, respectively.
In all cases, the known methods exhibit low selectivity towards the desired compounds and a relatively low conversion rate whereby they are regarded as unattractive for use on a commercial scale.
As a result of that opinion on the part of those skilled in the art, as, for example, transpires from column 2, lines 53-56, of U.S. Pat. specification No. 3,887,595, issued June 3, 1975, those skilled in the art have not been primarily inclined to direct further research towards that type of reaction in the search for methods for the preparation of cheaper and attractive base materials desired for further organic syntheses. On the other hand, the demand for cheaper base materials desired for further organic chemical syntheses has been steadily growing over the years.
The purpose of the invention is therefore to provide an improved method for the preparation of alpha,beta-olefinic unsaturated esters, acids or anhydrides.